Once Upon a Nightmare
by Tabbygal
Summary: We've all been waiting for it. Halloween Town is coming to Story Brooke and Oogie Boogie has plans that are far worse than just ruining Christmas.
1. Chapter 1

So this is one of my first times venturing into the crossover and really some of my first fan fic work. But I have been waiting way too long to see this actually happen in the show, so I'm just going to do it myself. Let me know what you think!  
Disclaimer: I do not own Once Upon a Time or Nightmare Before Christmas :/  
Enjoy!

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A lone figure shuffled through the darkest part of the woods on a Sunday night. Wind softly blew her brown hair out of her face as she wrung her hands in worry and kept walking. Her legs ached and her feet were so sort they felt like they would fall off, but she kept on walking. She wasn't sure where she was or where she was going. Still, she had to be going somewhere. Nothing looked familiar, which might have excited her at one point. Jack always liked to see or hear about new places and she would relish telling him about the silvery moonlight spilling through the trees or the way golden leaves crackled underneath her feet with every step.  
Sally glanced down at her hands again, reassuring herself that they were a human color. All the residents of Halloween Town knew how to disguise themselves in the human realm, the just seldom had the need. She was unused to the look of a pale, fleshy hand reflecting in the starlight.  
"Stop right there." A hard woman's voice ordered from her right. Sally turned to face a blonde in a red leather jacket.  
"Oh, I told Jack this wasn't going to end well. I've told him a million times, but he just never listens. And just a month before Halloween, that fool!" She twisted her hands together some more, giving a worried look to the rather confused looking blonde.  
"I'm sorry, I'm just going on to myself. I'm Sally, and I'm afraid I'm terribly lost. Could you tell me where I am?"  
The other woman who had at first appeared to be in a position to attack, relaxed. "StoryBrooke. Now how did you get in here? Nobody gets past the town line." Her posture said she was relaxed. Her words and her tone told Sally that she was still poised and ready to fight.  
"I'm not really sure. One minute I was getting ready to get married, the next I woke up in these lovely woods. I've been wandering for a while, hoping that I would find someone." She explained, offering a soft smile in attempts to calm the other woman. "What's your name?"  
The other woman stared for another moment, face still hard. Then she tucked the gun in her hand into the back of her pants and seemed to settle for eyeing Sally warily. "Emma. Come on, I'll take you into town, we'll get you on your way back home by the time morning comes." She said sharply, waving Sally forward. Sally hurried after Emma, tugging at her full black skirt and grimacing when she heard a rip. She had worked for weeks on making the wedding dress, she didn't want it ripped to shreds by the time she finally saw Jack. Still, Emma charged through the woods as someone that obviously knew them well and didn't intend to slow her pace for Sally. She had no choice but to hike up her skirts as much as she could and do her best to keep up.  
It didn't take too long for them to come to the edge of the woods. They stepped out onto a road where the oddest looking yellow car waited. Sally's hand timidly flitted out to touch the side of it. "How lovely." She said with a happy smile, looking over to the other side of the car where Emma was giving her a slightly confused and impatient look.  
"Thanks... It's my bug. Get in, I'll drive you to the station. The dwar- Some hikers said they saw someone out in the woods, so I'll have to let them know that I found you."  
Sally slipped into the car without a reply. She could tell that Emma was hiding something, she had really done some tripping over words, barely keeping from saying something. Sally was beginning to have a terrible feeling in the pit of her stomach about the strange town, remembering the odd premonition she'd had that morning.

 _Sally swept the comb through her hair once more, smiling at the way her brown hair was curling over her shoulders. She wore a tiara made entirely of spiders on her head and her dress was a lacy black material that the witches had spent hours creating. The result was breathtaking and Sally could hardly believe that she was wearing it. Still, it was nothing compared to the fact that she was getting ready to go marry Jack. That was a wonderful fact that she had yet to wrap her head around.  
She gazed into the mirror in front of her, allowing her mind to wander. Perhaps one day they would have a few skeleton children running around. Sally giggled a little at the thought, absently noticing the picture of a town forming in the mirror. She often had visions of strange places, so she didn't pay it too much mind. Until flames began to lick at the edges of the buildings. Soon, the whole town was engulfed in flames and screams echoed in Sally's mind. She gasped and pushed herself back from the dressing table. She had to go find Jack.  
Sally hurried from the back room in the town hall, ignoring the sound of ripping fabric as she carelessly tore through the doorway. She raced to Jack's house, a tower that reached for the sky, and pushed her way inside without knocking.  
"Jack! Oh Jack!" She called, starting up the stairs. He appeared at the top before she was halfway up and met her in the middle.  
"Sally! You look absolutely stunning, I fall in love with you more every day." He took both of her hands, looking at her in that way that always made her feel all muddle-brained inside. She almost forgot all about why she had come. But the picture of a burning town popped into her head again and she straightened up.  
"Jack, I had the most awful vision" She panted. He smiled.  
"How delightful!"  
Sally shook her head. "No, it truly was dreadful! There was a town, and it burned up. So many people were hurt, I could hear them screaming." She insisted, tugging on his hands. He had to grasp the importance of it, especially after what had happened over Christmas.  
The skeletal man just shook his head. "On our wedding day? Not a chance, nothing like that is going to happen. I won't allow it." He said confidently. Sally couldn't fight back the worry as easily.  
"But what if you can't stop it? Or what if we're supposed to, and we do nothing and it still happens? What if it's a sign-"  
"Stop worrying, Sally." Jack cut her off. "Everything is going to be fine. I'll have the mayor check the town to make sure everything is in order, and we shall assume that this disaster will hold off another day." He assured her, cutting off any further objections with a lingering kiss. _


	2. Chapter 2

Authors Note: Alright, I've decided that I'm probably going to update this story weekly, on Friday's. Any ideas or critique are welcome, though I can't promise that I will follow all of it! Thanks to everybody that's already read/followed/favorited/reviewed this3

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Emma glanced uneasily at the woman who sat beside her with a pleasant expression on her face. She couldn't quite pinpoint it, but something about the woman just sent unpleasant chills up Emma's spine. Something about her was dark and left a lingering sense of fear in the back of Emma's mind. As much as she wanted to ignore it, she knew better than to not trust those sort of vibes when she met new people. She'd had the same sort of feeling the first time she'd met Gold, though his had been much more malevolent. Sally just seemed...off.  
Emma had never been so grateful to see the town come into view. Sally gasped at the sight and Emma looked over sharply. "What?" She asked.  
Sally looked down into her lap, fingers twisting together. "Nothing. Just thought I recognized the town at first. I was wrong." She was lying. Emma could have picked that up from a mile away, but she didn't push the issue. Better to get her into the station first and call everybody up so they could decide collectively how to deal with the stranger. And find out if she knew what Storybrooke was, or if she really was just a passing stranger. Her story didn't quite ring true, but Emma hadn't seen any signs of the woman lying.  
"We're here." She said, pulling to a stop in front of the police station. Sally smiled politely and stepped out of the car.  
"I can talk to them from here. Thank you for bringing me."  
Emma followed her out, turning off the car and striding towards the station. "I am the sheriff. It's me you'll be talking to." She announced, glancing back to make sure that Sally was still following. Reassured that she was, Emma swung the door open then pulled out her cell phone, punching in a number and holding it up to her ear.  
 _"Hello? Emma, why are you calling this late?"_ Mary Margaret's sleepy voice sounded on the other end. A glance at the clock told Emma that it was already past eleven. Well, too late to turn back.  
"Sorry, I didn't realize it was so late. Listen, are you still up?" She asked. There was a shuffling noise and the sound of clothes rustling.  
 _"Uh, yeah. David and I were...cooking. What do you need?"_  
Emma rolled her eyes. "I found someone wandering in the forest. She's um.. Not from around here. Could you send Dad down here and call Regina?"  
More shuffling noises. _"Of course. Is everything alright? Do you think she's dangerous?"_ Her mother's voice was sounding increasingly worried.  
"Yeah, it's fine. And no-" Emma looked over at Sally who had taken a seat and was curiously flipping through a magazine. "I don't think she is."  
 _"Alright, we'll be over in a few. I'm coming too."_  
"No, mom, that's not-" She was cut off by the sound of the phone being hung up. Growling and cursing under her breath, she slipped the phone back in her pocket. Sally looked up at her.  
"What was that?" She asked.  
"You mean my phone?" Emma questioned.  
Sally pointed at her pocket. "The thing that you were talking into."  
 _Definitely not from the current realm. Great, another fairy-tale._ She thought inwardly. "It's called a phone. It's for contacting people from long distances." She explained, having the words ready from all the times she'd had to explain it to people. "And no, it's not magic."  
Sally frowned. "How odd. Is it common here?"  
"Here as in the world that we're in? Yes. Where exactly are you from?"  
The girl looked Emma unabashedly in the eyes. "Where are you from, Sheriff?"  
Emma met the look and crossed her arms. "New York."  
"Oh." Sally said, growing quiet after that and never actually answering Emma's question. She looked back down at her magazine and resumed reading. Emma considering pushing the question, but decided to wait for everyone else to get there before trying to figure it out. The room fell into an uncomfortable silence, filled with nothing but the ticking of the clock on the wall and the occasional swoosh of Sally flipping a page.  
She'd never been so grateful for the clamor of multiple people entering the station at once and she hurried over to meet them, seeing her parents, Regina and..Dr. Wale?  
"Thanks for coming. Um, why exactly is he here?" Emma asked, giving a curious look towards the doctor. He pushed his way forward and Regina sighed.  
"I just saw everyone heading this direction and figured it was about to be the start of some other town-threatening event. I thought I might as well tag along, see what everyone's been up to. I was beginning to feel rather left out, you know."  
"Can we please just ignore that he's here and get on with it?" Regina asked, shooting the doctor an annoyed glance.  
"Emma, who is this girl?" Mary Margaret asked.  
"I don't know. The dwarves said they saw someone in the woods so I went to check it out. She was wandering around lost. Says her name is Sally." Emma spouted everything she knew about the woman, realizing just how little that was. Regina looked over at her and narrowed her eyes.  
"She's using some sort of spell to cover up how she really looks." She announced striding forwards. Sally looked up, concern sweeping across her face. She started to protest, but a waved hand from Regina silenced her and her image shimmered, then changed. Her general form was still the same, but her skin looked like blue fabric, patched together in different areas and at every joint. A cold chill blew through the room and the unsettled feeling Emma first had when she met Sally turned up to a feeling of unnatural fear.  
"Sally?" Wale asked, pushing his way to the front of the group.  
"You know her?" Emma demanded.  
"I created her!"  
"Dr. Finklestein?" Sally asked, shooting upright. Regina dropped her hand and Sally's appearance went back to that of a normal human and the unnatural chill in the air faded. Wale turned back to face her looking freshly annoyed.  
"It's Dr. Frankenstein. Not Finklestein. I don't know why nobody in your god-awful town can grasp that, but name never has, and never will be, Finklestein." He snapped. Sally just crossed her arms and glared at him, sniffing.  
"What town exactly are you two talking about?" Regina asked.  
"Halloween Town." Wale answered, still involved in a glaring match with Sally. Regina groaned and rubbed the bridge of her nose.  
"God, I hate that place. It's even worse than Wonderland. Trust me, nothing good ever comes out of that place." She warned with a dark look towards Sally. Then she turned to Wale. "What were you doing there?"

"What do you think? I was working. The lines between life and death are blurred there, I thought I could finally reach a breakthrough. And I did. Sort of." He said, gesturing to Sally.  
"What do you mean, sort of?" David asked, finally speaking up.  
Wale appeared to be in a silent struggle for words for a moment. "I did manage to create Sally, the process is incredibly complicated, I won't try to explain it to you. There was a heart and she's actually made out of cloth an leaves, plus parts of my brain which I'm not even going to get into. But although she's moving and breathing and thinking, she's still not actually alive. She's just...not dead."  
"I am just as alive as any other resident of Halloween Town!" Sally exclaimed, stomping her foot angrily. Wale just shook his head.  
"Actually, you're a little bit more alive, considering almost everybody else there is actually dead. Or undead... It's very difficult to wrap the head around actually, the town keeps all the residents in a sort of limbo state, keeping them breathing and thinking and moving, though none of them are technically alive. They can leave the town for brief periods of time, but extended periods could have poor results." He said grimly.  
Sally sat back down suddenly, looking much paler than she had a few minutes earlier. She went back to wringing her hands in worry.  
"Alright, let's not jump to any conclusions just yet. We need to get her back to Halloween Town, but we don't exactly have access to any magic beans or any other sort of portal openers." Emma reasoned. Wale shrugged.  
"That's easy. Any graveyard in this world should have a portal to Halloween Town. That's how they get her for Halloween."  
"Great." Regina said. "Take her to the graveyard, dump her through and brush our hands off. Good deed done and we can all go to bed."  
"I can't leave yet!" Sally cried, standing again and beginning to pace.  
"Why not?" Emma asked sharply.  
"I have to find Jack. I'm just sure that he wound up here too, and not to mention the terrible premonition I had this morning. Oh, I knew that something terrible would happen, I just knew it." She fretted, pacing faster and faster as she talked.  
Wale groaned. "Seriously, Jack's going to show up here? We're all screwed." He announced, turning a shade whiter.  
"It's your own fault, Finklestein." Sally snapped at him.  
Emma stepped between the two and held her hands up. "Okay, who's Jack, why should we be afraid of him, how is it Wale's fault and what premonition did you have?" She asked, giving Wale a glare that convinced him to take a step back.  
Sally's pacing slowed. "Jack is my fiancee, and the Pumpkin King. He's the one that leads the town, and he probably won't do anything horrible. Frankenstein locked me up in his house for years after he created me. He wouldn't let me leave for anything!" Sally claimed, giving Wale a withering glare.  
"You weren't ready for all the excitement, I still had to make sure you weren't going to fall apart." Wale shot back.  
"So, she shares parts of your brain and you locked her up in your house for years? Oh, I could say so much on this." Regina said with a smirk.  
Wale made an ugly face. "Don't even go there. She slipped deadly nightshade into my tea once. It almost killed me!"  
"Deadly nightshade doesn't kill people, it just puts them to sleep." Sally protested.  
"Only for undead people! The rest of us, it kills. Hence the _deadly_ part in it's name." He argued, waving his hands for emphasis.  
"Can we please get back to the point of this?" Emma asked.

Sally paused a moment, biting her lip like she was deciding whether or not she should share. Apparently she decided to, because she started to speak again. "I saw this town in my mirror this morning. At first it was just normal, but then all of it lit on fire and I heard these awful screams, it was liking watching a nightmare." She shuddered and fell back into her chair, a faraway look in her eye.  
"Okay, we need to lock her up." Regina decided.  
"Agreed." Wale said, glancing down when his phone went off. "Whoa, looks like someone took a nasty fall. Look at this." He shoved his phone out and everybody turned away from the gory picture on it. Well, everybody but Sally who just peered over in interest. "Anyway, I gotta go. Better stitch em' up before they die of bloodloss and wind up in Halloween Town somehow. Wale-out." He said, tucking his phone away and disappearing out the door.  
"Wait, are we talking about locking poor Sally up? She hasn't done anything wrong. We should be helping her." Mary Margaret protested.  
"Her fiancee could possibly be threatening this town and she has a premonition about Story Brooke burning, then randomly appears here? I think it's safe to assume she's fairly involved in the whole town burning thing, so if we keep her away from the general public, maybe we can keep disaster from striking until we figure this thing out." Regina continued, looking down on Mary Margaret.  
"She hasn't done anything though. We can't just lock away everything that we construe as dangerous." She insisted. David moved forward, placing a hand on her back.  
"Mary Margaret's right. We need to help her, not just put her away like some sort of criminal."  
Regina rolled her eyes and put her hands on her hips. "I'm not saying we lock her in a dungeon and starve her or anything. Just keep her in the clock tower or something till we figure out what's going on." All three of them suddenly turned to face Emma and she knew it was down to her to cast the deciding vote.  
"Honestly, I'm with Regina on this one. The clock tower is a fair comfortable place, we'll make sure she isn't lacking anything and we'll try to figure out what her vision meant."


End file.
